Thermal fatigue of single-crystal superalloys: experiments, crack-initiation and crack-propagation criteria

Abstract

Thermal-fatigue tests were performed on corset samples made from five single-crystal nickel-based superalloys with various crystallographic orientations ( 001 , 011 , 111 ) at different temperatures and cycle durations. The proposed criteria for the thermal-fatigue crack initiation and crack propagation are discussed and compared with experimental results. The sensitivity of durability to the crystallographic orientation and to thermal-cycle parameters is analyzed experimentally and by means of the corresponding finite-element simulations.